Prophylactic Anticoagulation for Central Venous Line Insertion in Critically Ill Children

The study population will be divided into two groups:

• Enoxaparin Group (Anticoagulation Arm):

This group will receive prophylactic anticoagulation with enoxaparin in accordance with institutional guidelines for prophylactic anticoagulation in Pediatric patients.

• Usual Care Group (Control Arm):

This group will receive standard care without prophylactic anticoagulation.

All patients in this study will be subjected to:

A- Demographic and clinical data Collection:

• Patient demographics: age, sex, body mass index (BMI) and the primary diagnosis.
• CVC characteristics: type of line, number of lumens, catheter size, site and laterality, and date of insertion and removal.
• Thrombotic events: date of thrombus detection, affected blood vessel (confirmed by Doppler ultrasound), and anticoagulation details (type, dose, and duration. (
• Anticoagulant use: agent used (e.g., LMWH), initiation timing and monitoring. B- Full clinical examination will be done including vital signs (HR, RR, BP, temperature) for each child.

C- Investigations will be done including the following:

Laboratory Analysis: CBC, Platelet counts at baseline, day 3-5, for monitoring heparin- related thrombocytopenia, CRP, Electrolytes, Blood culture, Urea, creatinine, ALT, AST and D-dimer level.

Radiological: Ultrasound of catheterized vessel if clinical suspicion of thrombosis; consider scheduled ultrasound on day 7 and 14.

Intervention and Monitoring

Enoxaparin Group (Intervention Arm):

• Children randomized to receive enoxaparin will be administered enoxaparin subcutaneously every 12 hours, with dosing based on age and weight as follows:

• 0.75mg/kg for children ≤2 months old.
• 0.5 mg/kg (maximum 30 mg) for children >2 months old.
• Doses will be adjusted for obesity and renal insufficiency as needed.
• The first dose will be given within 24 hours of CVC insertion. The dose will be adjusted to achieve a target anti-Xa level of 0.2-0.5 IU/mL.
• Anti-Xa levels will be measured locally 4-6 hours after every third dose, and dosing will be adjusted accordingly until the target range is reached. Once therapeutic range is achieved, anti-Xa monitoring will be performed weekly.
• Enoxaparin will be discontinued in the event of a clinically significant bleeding episode. It will be resumed 24 hours after correction of any coagulopathy, as confirmed by clinical and laboratory parameters.

Usual Care Group (Control Arm):

Children randomized to usual care will not receive anticoagulation. Standard CVC care procedures will be followed according to PICU protocols.

Monitoring for Thrombosis and Bleeding

• All children will undergo daily clinical monitoring for signs of bleeding.
• To evaluate catheter-related thrombosis, ultrasound imaging of the vein proximal and distal to the CVC insertion site.
• To assess coagulation profile and thrombotic risk, blood samples will be drawn at the following time points:

• On the day of CVC insertion
• The day after insertion
• Day 4 after insertion

Inclusion criteria

• All Children requiring a newly placed central venous line (peripherally inserted central catheter [PICC], or non-tunneled central venous catheter) for clinical care.

Exclusion criteria

• Known major congenital bleeding diathesis or platelet count <50,000/µL at time of insertion.
• Already on therapeutic anticoagulation for another indication.
• Known heparin allergy or history of heparin-induced thrombocytopenia.
• Use of dialysis catheters (study focuses on standard CVCs/PICCs).